GaAs/Ga0.47In0.53As lattice-mismatched Schottky barrier gates: Influence of misfit dislocations on reverse leakage currents

Abstract
Epitaxial GaAs has been grown on Ga0.47In0.53As by molecular beam epitaxy to form a lattice‐mismatched Schottky barrier gate for field‐effect transistor applications. The study of cross‐sectional transmission electron microscopy shows that the misfit dislocations accommodating the 3.7% lattice mismatch between these two materials are confined in a GaAs interfacial layer of 300–400‐Å thickness. As a result of significant reduction in dislocation densities, Schottky barrier gates made on a sample having a 960‐Å‐thick GaAs layer exhibit reverse leakage currents two orders of magnitude lower than those made on a sample with a 580‐Å‐thick GaAs layer. This approach looks promising for fabricating Ga0.47In0.53As field‐effect transistors for optoelectronic integration as well as high‐speed logic applications.